Renewable fuse



|. MARCUS.

- RENEWABLE FUSE.

APPLICATION FILED FEB. 13, 1919.

Patented NOV. 14, 1922.

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RENEWABLE FUSE.

APPLICATION FILED FEB. I3, I9I9.

1 ,435,31'7. Patented Nov. 14, 1922*..`

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UNITED STATES 1,435,317 PATENT OFFICE. i

ISRAEL MARCUS, F WINTHROP, MASSACHSETTS.

RENEWABLE FUSE.

Application led February 13, 1919. Serial No. 276,783.

To all whom it may concern.'

Be it known that I, ISRAEL MARCUS, a citizen of the United States, residing at Winthrop, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Renewable Fuses; and I do declare'thefollowingl to be a full,'clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to improvements in fuses used in electric circuits to protect the several loads thereon and the gen/4^ erator in case. of short circuit to any particular load or if the strength of the, current is suddenly increased from any other cause.

One object of the invention is to provide a quickly and easily renewable fuse having few partswhen opened for the installation of a new fuse wire.

Another object is to decrease the Hash when the fuse blows and to allow the generated gases but no flame to esc-ape.

A further object is to provide a fuse having a resistance wire toact after blowing of the fuse Wire, as a substitute-for the resistance previously offered by any load in the circuit'which may have been negatived lowing other loads on the A to operate.

With the foregoing objects in view, the invention resides in the novel features of construction and unique association of parts hereinafter fully described and claimed, and shown inthe accompanying drawings.

Figure 1 is a side elevation of the improved fuse.

Fig. 2 is a similar View with the caps, on

. the ends of the fuse body, in section.

Fig. 3`is a longitudinal section ofthe entire fuse.

Fig. 4 .is a similar view of the insulation circuit to continue bogy.

ig. 5 is a second longitudinal section as indicated by the line 5-5 of Fig. .3

Figs. 6,7, 8 and 9`are transverse sections on the planes of the lines 6-6,7-,7, 8 8 and 9-9 respectively of Fig. 5.-

-In the drawings above briefly described, the' numeral 1 designates an elongated preferably cylindrical bodyof insulation having` screw threads 2 on its end portions and provi'ded with a longitudinal recess 3 in -one 'si de the ends of said recess extending into by short circuit or other cause, thereby althe short ends 7 of the contact plates 4 being preferably inserted in recesses 8 in the ends of the body l. r

A. suitable fuse Wire 9, preferably though not necessarily of flat formation, is rernovably secured by screws or the like 10 against the inner ends of the contact plates 4, and a high resistance wire 11 connects the ends of the fuse to take the load from the fuse when the latter blows. 3This has avnumber lof advantagesto behereinafter fully set forth. The resistance wire 11 is located in a channel 12 formed in the bottom wall of the recess 3 and is thus segregated from the fuse wire 9.

An insert 13 of insulation` is removably` received in the recess 3 and is provided on its ends with screw threads 14 coinciding with the threads 2, and a pair of caps 15 of any preferred material are threaded over 80 the ends of the body 1 and saidinsert 13. This secures the insert snugly. in place, yet by unscrewing the caps 15 until theends of the insert are freed, said insert may -be quickly and easily removed to permit the installation 'of anew fuse wire. Particular emphasis is laid upon the fact that the caps 15 need not be entirely removed and thus there will be considerably lessA trouble and expenditure of time.

he outer ends of the caps 15 are formed with openings 16 through; which terminals 17 pass, the inner ends of said terminals havin contact lates 18 abutting the short arms of the pates 4, said plates 18 being 95 `held in proper engagement with the arms 7 by washers 19 against which the ends of the caps bear. Each terminal 17 is preferably formed of a single strip of metal folded upon itself withfits ends bent optward in opposite directions to form the contact plates 18, and to' insure-proper relation of said terminals with'the'body 1 at all times, certain ofthe plates 18 are providedwith lugs 20 ,receivable inv sockets 21`infthe` ends of the ner as to direct a surplus of current through the other loads', the'fuse wire 9 will immediately blow. The moment this blowing occurred, there would be a tremendous flash and generation of gases, were it not for the high resistance wire 11. This wire, however, takes -some loadfrom the fuse to decrease the Hash, but immediately after blow ing of the main fuse 9, the wire 11 becomes red-hot and blows als In orderl t insert av new fuse wire, it is simply necessary to partly unscrew the caps 15, remove the insert 13, detach the old fuse wire by removal of the screws 10, and to then form and serving to permit the escape of the generated gases when the fuse wire blows,

-although not allowingany flame to escape. l

Still another feature which may be employed, is the provision of flanges 26 arranged one on the insert 13 and one on the body 1 for receptionin the groove 27 with which vsaid body (see Fig. 6). By this arrangement, (the insert and body may be quickly centered for threading of the caps 15 over the ends of the former.

AFrom the foregoing, taken in connection with the accompanying drawings, it will be obvious that although the invention is of rather simple and inexpensive nature, it will be highly eiiicient and in every way desirable,

particular emphasis being laid upon the co-` operation existing between the body 1, the insert 13, and the caps 15, upon the construction and arrangement of the terminals 17, upon the high resistance wire 11, and

upon the zig-zag openings 25. Since probably the, best results are obtained from the s precise arrangement shown and described, it may be followed, but within the scope of the v claimed numerous minor changes may well be made, as occasion may dictate.

I claim:

^ 1. A renewable fuse comprising an elongated lbody of' insulation v.having threaded end portions and provided in one side with a recess whose ends extend into said thread-- and insert are provided ed end portions of the body but terminate in spaced relation with the ends of the latter, a renewable fuse wire in said recess, an insert snugly received in said recess and having threads on its ends coincidingl with the threads of said body, caps threaded over the ends of said body and insert, and means for placing the ends of said fuse wire in electrical connection with the usual fuse clips.

2. A renewable fuse comprising an elongated body of insulation having threaded end portions and provided in one side with a recess whose ends extend into the threads of the body but terminate in spaced relation with the ends of said body, the bottom wall of said recess having a fuse receiving cavity and the ends of said body being formed with longitudinal passages extending to the ends of said cavity, a pair of contact plates in said passages having means at their inner ends for attaching a fuse thereto, the outer ends of said plates being exposed at the'ends of said body, an insert in said recess, caps threaded on the ends of said body and extending over the ends of said insert, and terminals removable with said caps and normally in contact with said Contact plates.

3. A device of the class v'described comprising an elongated body of insulation, a pair of metallic Contact plates at the ends of ends to said Contact plates, a pair'of caps secured on the ends of said body, said caps having openings, and terminals passing through said openings, said terminals being each formed of a single strip of metal bent -upon itself with its ends bent laterally withinits respective cap-to form contact plates engaging said first named contact plates.

4. A renewablefuse comprising a flat strip having a narrowed fusible intermediate lpor.- ton and provided at its ends with openings to receive fasteners, Sand a high resistance wire extending around the fusible portio'rr'of said strip and permanently securedv at its ends to* said strip in electrical engagement therewith, said high resistance wirel forming with said strip a single articleof manufacture, belng adapted to carry a portion of the load lwhlle said strip is blowing and being 'then adapted'to fuse, `thereby reducing the ISRAEL MARCUS.

lsaid body, a' fuse in said body secured at its 

